A complex of technological operations for the formation of a cathode liner based on manganese dioxide is of particular importance in the production of tantalum oxide-semiconductor capacitors. Electrical characteristics and reliability indicators of capacitors are laid at this stage in their manufacture. In according with the classical technology, the formation of a semiconductor coating of MnO2 on tantalum capacitors is associated with multiple heating of oxidized anodes with the previous impregnation in solutions of manganese nitrate. It has a negative effect on the quality of the Ta2O5-dielectric. To minimize the defect formation in the dielectric, is realized a periodic electrochemical anodization of the tantalum anode in the acetic acid solution by anodic connection of the sections of the capacitors to the direct current source. The authors proposed to modify the process of reanodization of sections of tantalum oxide-semiconductor capacitors by changing the composition of the electrolyte. The results of the investigation of the electrochemical anodizing of a tantalum anode in aqueous solutions of nitric acid and manganese nitrate are presented, the morphology of the obtained coatings, their phase composition, as well as electrical parameters of the sections of capacitors manufactured by the proposed method are analyzed.

Keywords: Tantalum oxide-semiconductor capacitor, reanodization, manganese nitrate, capacitance, leakage current, dielectric loss tangent, electrolyte

In recent years, the most widely used semiconductor oxide-tantalum capacitors in high frequency circuits acquired, which causes the need to reduce resistance of the contact and the semiconductor layers. One solution to this problem and at the same time, promising way of improving solid-state tantalum capacitors is to modify process technology for applying the semiconductor layer and heat treatment resistive coating of colloidal graphite. Contact carbon layer according to conventional technology is applied by impregnating the tantalum capacitor sections in an aqueous suspension of colloidal graphite (usually imported), and then produce exposure to air and heat treatment at an elevated temperature. This article presents the results of studies of the effect of conditions of application of the contact layer of colloidal graphite on the electrical characteristics of sections of tantalum oxide-semiconductor capacitor, in particular in the equivalent series resistance, the technique of applying aquadag. Described in detail the design of solid-state tantalum capacitor, the role of the contact carbon layer and its contribution to the ESR of the capacitor.

Keywords: oxide-semiconductor capacitors, colloidal graphite, resistance of the capacitor, the cathode coating, suspension, immittance, aquadag

"One of the bottlenecks of the production of oxide-semiconductor capacitors is enough fast aging of impregnating solutions of manganese nitrate used to form the cathode electrode of manganese dioxide. This effect is caused by the formation and accumulation of impurities of oxides and nitrides of manganese in the solution, which leads to a poor-quality cathode coating of manganese dioxide on the tantalum anode and as a result, poor performance capacitors. Fast aging of impregnating solutions of the Mn(NO3)2 solutions leads not only to an increase in the cost of materials, but also significantly increases of the volume of waste. As a solution to this problem in the proposed article discusses aspects of chemical regeneration of contaminated solutions of manganese nitrate, analyzed the possible ways of its realization in relation to the existing production of oxide-semiconductor capacitors."

Keywords: Manganese nitrate, manganese oxides, cathode coating, impregnating solutions, manganese nitrides, manganese oxohydroxide, chemical regeneration.